Introduction to the selection of substrates for coated steel sheets

The substrate can be cold-rolled substrate, electro-galvanized substrate, hot-dip galvanized substrate, galvanized steel plate, and materials with mechanical properties should be selected according to different uses.
Cold rolled substrate
The coated steel plate produced by the cold-rolled base plate has limited corrosivity, and if the surface is scratched, red rust will appear and affect the use. The film-coated steel plate of this substrate can be used to make the housing of household appliances, or to be used for temporary isolation fences with low height.
Galvanized substrate
The coated steel plate of the electro-galvanized substrate is protected by the zinc layer, and its corrosion resistance is higher than that of the cold-rolled substrate coated steel sheet. Because the zinc layer is thin (generally zinc content is 20g/m2), its processing performance is better than that of hot-dip galvanizing. When making products and components that require corrosion resistance, the coated steel plate with electro-galvanized steel plate as the substrate can be considered. Such as the internal and external components of air conditioners, the shell of washing machines or refrigerators; walls, furniture, lighting equipment, signs, etc. for interior decoration.
Hot-dip galvanized substrate
The hot-dip galvanized substrate can be selected according to the amount of galvanizing, the shape of the zinc layer and the surface finish.
1. Galvanizing amount
Different galvanizing amounts should be selected according to different use environments. The galvanizing amount of hot-dip galvanized sheets used for coated steel sheets is usually 180 g/m2 (double-sided), and 275 g/m2 is best used in industrial and coastal areas. Meters (both sides) of galvanizing.
2. Surface finishing of zinc layer morphology
The formability of zinc-iron alloyed hot-dip galvanized sheet is worse than that of ordinary hot-dip galvanized sheet, so ordinary hot-dip galvanized sheet is generally used as the substrate. Generally, hot-dip galvanized sheets with ordinary spangles, small spangles, and no spangles can be used as coated substrates. In order to improve the surface condition of hot-dip galvanized sheets and make them suitable for coated sheets, they generally have to be leveled (or smoothing) and straightening.
Galvalume steel plate
Since the galvanized steel plate was promoted to the market in the 1970s, it has become the most popular steel plate for roofs and walls. The hot-dip alloy coating of galvanized steel plate contains 55 aluminum, 43.5 zinc and 1.5 silicon, which perfectly combines the advantages of steel plate strength, aluminum corrosion ability and zinc’s ability to protect against cuts and intermittent sacrifices. In a similar environment, the service life of galvanized steel sheets with the same coating thickness is about four times that of galvanized steel sheets. Galvalume-galvanized steel plate is a cost-effective product, its cost is far lower than that of stainless steel plate or aluminum plate, and it has a pleasing light silver-gray bright appearance.